Knight Of Honor refers to the personal bodyguards recruited by a princess of the Imperial Family, in the way Euphemia Li Britannia employed Suzaku and Cornelia employs Guilford. There have been exceptions, as Charles zi Britannia employed the Knights of Rounds and Lelouch had Suzaku Kururugi (the Knight of Zero).
Eligible Knight of Honor Candidates For Euphemia li Britannia selected by Cornelia.
Upon recieving this title, in service of Euphemia, Suzaku was granted a promotion to Major.